Add better error messages for unavailable swarm commands
Add better error messages for unavailable swarm commands

Signed-off-by: Tonis Tiigi <c2470c48b2d3312d61f94f18d3a1cd113d1915ad@gmail.com>
(cherry picked from commit 803733120a1f9f080c6403f2a3717987393f1f0d)

danix800/docker.github.io,JimGalasyn/docker.github.io,denverdino/docker.github.io,shubheksha/docker.github.io,docker-zh/docker.github.io,JimGalasyn/docker.github.io,stainboy/docker,LuisBosquez/docker.github.io,gdevillele/docker.github.io,alexisbellido/docker.github.io,denverdino/denverdino.github.io,docker-zh/docker.github.io,BSWANG/denverdino.github.io,aduermael/docker.github.io,medallia/docker,denverdino/denverdino.github.io,LuisBosquez/docker.github.io,aduermael/docker.github.io,sanscontext/docker.github.io,shubheksha/docker.github.io,troy0820/docker.github.io,phiroict/docker,alexisbellido/docker.github.io,sanscontext/docker.github.io,shin-/docker.github.io,denverdino/denverdino.github.io,anweiss/docker.github.io,bdwill/docker.github.io,joaofnfernandes/docker.github.io,joeuo/docker.github.io,jzwlqx/denverdino.github.io,phiroict/docker,denverdino/docker.github.io,troy0820/docker.github.io,BSWANG/denverdino.github.io,londoncalling/docker.github.io,menglingwei/denverdino.github.io,sanscontext/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io,joaofnfernandes/docker.github.io,shin-/docker.github.io,shin-/docker.github.io,menglingwei/denverdino.github.io,gdevillele/docker.github.io,medallia/docker,danix800/docker.github.io,sanscontext/docker.github.io,sanscontext/docker.github.io,thaJeztah/docker.github.io,phiroict/docker,joaofnfernandes/docker.github.io,rillig/docker.github.io,LuisBosquez/docker.github.io,troy0820/docker.github.io,shubheksha/docker.github.io,aduermael/docker.github.io,medallia/docker,jzwlqx/denverdino.github.io,shin-/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,shubheksha/docker.github.io,stainboy/docker,thaJeztah/docker.github.io,johnstep/docker.github.io,docker/docker.github.io,Shopify/docker,BSWANG/denverdino.github.io,joeuo/docker.github.io,phiroict/docker,johnstep/docker.github.io,BSWANG/denverdino.github.io,johnstep/docker.github.io,jzwlqx/denverdino.github.io,menglingwei/denverdino.github.io,joaofnfernandes/docker.github.io,denverdino/docker.github.io,anweiss/docker.github.io,bdwill/docker.github.io,thaJeztah/docker.github.io,gdevillele/docker.github.io,JimGalasyn/docker.github.io,thaJeztah/docker.github.io,jzwlqx/denverdino.github.io,joaofnfernandes/docker.github.io,alexisbellido/docker.github.io,shubheksha/docker.github.io,jzwlqx/denverdino.github.io,docker/docker.github.io,joeuo/docker.github.io,bdwill/docker.github.io,anweiss/docker.github.io,danix800/docker.github.io,denverdino/denverdino.github.io,docker/docker.github.io,troy0820/docker.github.io,joeuo/docker.github.io,phiroict/docker,shin-/docker.github.io,JimGalasyn/docker.github.io,johnstep/docker.github.io,alexisbellido/docker.github.io,johnstep/docker.github.io,rillig/docker.github.io,stainboy/docker,anweiss/docker.github.io,anweiss/docker.github.io,denverdino/denverdino.github.io,denverdino/docker.github.io,menglingwei/denverdino.github.io,menglingwei/denverdino.github.io,alexisbellido/docker.github.io,bdwill/docker.github.io,docker-zh/docker.github.io,medallia/docker,aduermael/docker.github.io,bdwill/docker.github.io,LuisBosquez/docker.github.io,docker/docker.github.io,BSWANG/denverdino.github.io,joeuo/docker.github.io,gdevillele/docker.github.io,JimGalasyn/docker.github.io,docker-zh/docker.github.io,rillig/docker.github.io,docker-zh/docker.github.io,Shopify/docker,gdevillele/docker.github.io,rillig/docker.github.io,danix800/docker.github.io,londoncalling/docker.github.io,LuisBosquez/docker.github.io,Shopify/docker,denverdino/docker.github.io,londoncalling/docker.github.io